Other Information

Understanding SEER vs SEER2

What is SEER?

SEER stands for Seasonal Energy Efficiency Ratio. It measures the cooling efficiency of an air conditioner or heat pump over an entire cooling season. Essentially, it tells you how much cooling output (BTUs) you get for every unit of energy (watt-hour) used.

• Higher SEER = more efficient

• SEER ratings have traditionally been used in the U.S. to compare energy efficiency across systems.

• Example: A 14 SEER unit uses less electricity than a 10 SEER unit to produce the same cooling.

What is SEER2?

SEER2 is the updated efficiency rating standard that reflects new federal testing procedures implemented by the Department of Energy (DOE) in 2023. It measures efficiency more accurately by accounting for real-world conditions, including:

• Energy usage in modern airflow and installation configurations

• More realistic climate and seasonal variations

• Changes in the refrigerants and equipment designs

Key difference: SEER2 ratings tend to be slightly lower than SEER ratings for the same unit, but they provide a truer representation of actual efficiency in your home.

Why SEER2 is the new standard

• The DOE updated testing to better match how systems perform in real homes, rather than ideal lab conditions.

• It encourages manufacturers to improve real-world efficiency, not just test-case efficiency.

• For consumers, SEER2 ensures:

  • Better long-term energy savings

  • Improved comfort through more accurate performance expectations

  • Compliance with modern federal efficiency regulations

In short:

• SEER = old efficiency measurement (ideal lab conditions)

• SEER2 = modern, realistic efficiency standard (real-world performance)

• Better quality = SEER2 units are designed and tested to give actual efficiency and savings, not just theoretical numbers.

Understanding EER vs EER2

What is EER?

EER stands for Energy Efficiency Ratio. It measures an air conditioner or heat pump’s efficiency at a single, specific outdoor temperature, usually 95°F.

• Higher EER = more efficient at peak conditions.

• Unlike SEER, which averages efficiency over a season, EER tells you how the unit performs under hot, steady-state conditions.

• Example: A unit with an EER of 12 produces 12 BTUs of cooling for every watt of electricity consumed.

What is EER2?

EER2 is the updated testing standard introduced by the Department of Energy (DOE) to match the same real-world adjustments as SEER2.

• Accounts for modern system designs, refrigerants, and installation configurations.

• Measures efficiency more realistically under peak operating conditions, rather than just ideal lab setups.

• Like SEER2, EER2 numbers are usually slightly lower than traditional EER, but they are a more accurate reflection of actual performance.

Why EER2 is the new standard

• Ensures consistency with SEER2 testing methodology.

• Reflects true cooling efficiency under extreme heat, where peak performance matters most.

• Helps consumers understand real-world energy use and savings potential during the hottest days.

• Meets modern federal efficiency regulations and encourages manufacturers to improve performance under actual conditions.

In short:

• EER = old standard, measured under lab conditions at 95°F

• EER2 = modern standard, measured under realistic, real-world peak conditions

• Better quality = EER2 gives you true peak efficiency, not just theoretical performance.